Electronic device, panel device, and supporting rail

ABSTRACT

A rear opening of a housing  1  is covered by a first plate member portion  35  of a member  4 . Heat generating elements  26  and  31  are mounted on a second plate member portions  36  of the member  4 , which are elongated from the first plate member portion  35  and which are positioned in the housing  1 , thereby causing the back face of the first plate member portion  35  to face the outside of the housing  1 . A support rail attaching portion  38  is disposed on the back face. The first plate member portion  35  is grounded via a DIN rail  34  attached to the portion. Even when the housing is configured by a resin, therefore, heat generated by the heat generating elements in the housing can be efficiently discharged to the outside of the housing, with the result that an electronic device of excellent heat radiating properties is obtained.

TECHNICAL FIELD

The present invention relates to an electronic device which comprises aheat generating element in a housing, such as a power source device, atimer, or a temperature adjuster, also to a panel device in which pluralsuch electronic devices (a concept including all such as an electricapparatus and an electronic apparatus) are usually accommodated in asame panel with the object of control, monitor, or the like, and also toa support rail which is used for supporting such an electronic device insuch a panel in a juxtaposed state, such as a DIN rail.

BACKGROUND ART

As an electronic device which comprises a heat generating element in ahousing, for example, known is a power source device such as a switchingpower source. The power source device incorporates a heat generatingelement such as a switching transistor or a rectifying diode in ahousing. In such a power source device of the conventional art, ahousing is configured by a material which is inferior in heat radiatingproperty than a metal, such as a resin. The device incorporates a heatgenerating element and a heat radiating member which radiates heatgenerated by the heat generating element, in the housing. The heatradiated from the heat radiating member is discharged to the outsidethrough a large number of heat radiating slit holes which are formed ina side portion of the housing.

In a power source device of another conventional art example, a housingmay be configured by a material which is superior in heat radiatingproperty, such as a metal. A heat radiating member is placed in thehousing, and heat from the heat radiating member is conducted also tothe housing, thereby improving the heat radiation efficiency.

(Technical Problems that the Invention is to Solve)

In the former power source device, however, the periphery of the heatradiating member is covered by the housing made of a resin which is amaterial having inferior heat radiating properties, and hence there is aproblem in that, even when many heat radiating slit holes are formed inthe housing, heat of the heat radiating member is hardly dissipated tothe outside of the housing, thereby impairing the heat radiatingproperties of the device.

By contrast, in the latter power source device, the side portion of thehousing is configured by a metal which is a material having superiorheat radiating properties. Therefore, the device is superior in heatradiating property than the former device. Since the housing material isa metal, however, an insulation distance from the housing must be set tobe relatively large so as to prevent an electronic component in thehousing from being in contact with the housing. Therefore, the latterpower source device has a problem in that, even in the case of a powersource of a small capacity, the size of the housing is large and hencethe device cannot be made compact and is heavy, with the result that itis very difficult to handle the device.

It is a common object of the invention to provide an electronic devicein which, even when a housing is configured by a material such as aresin which is inferior in heat radiating property than a metal, heatgenerated by a heat generating element in the housing can be efficientlydischarged to the outside of the housing, and which therefore hasexcellent heat radiating properties.

DISCLOSURE OF INVENTION

(Solving Method and Effects Superior than Conventional Art)

In order to attain the object, a first feature of the invention is anelectronic device comprising: a housing; a first metal member havingportions which face to an inside and an outside of the housing,respectively, and attached directly or indirectly to the housing; and aheat generating element which is attached to the portion of the firstmetal member, the portion facing the inside of the housing.

According to the first feature, even when the housing is configured by aresin which is inferior in heat radiating property, for example, heatgenerated by the heat generating element attached to the portion of thefirst metal member facing the inside of the housing is easily radiatedto the outside of the housing through the portion of the first metalmember facing the outside of the housing. Therefore, the electronicdevice has excellent heat radiating properties.

A second feature of the invention is an electronic device comprising: ahousing; a first metal member facing an outside of the housing; a secondmetal member which is formed integrally with the first metal member, orcoupled to the first metal member directly or via another metal member,and which is located in the housing; and a heat generating element whichis attached to the second metal member.

According to the second feature, even when the housing is configured bya resin which is inferior in heat radiating property, for example, heatgenerated by the heat generating element attached to the second metalmember is conducted from the second metal member to the first metalmember. Since the first metal member faces to the outside of thehousing, the generated heat is easily radiated to the outside of thehousing. Therefore, the electronic device has excellent heat radiatingproperties.

A third feature of the invention is an electronic device in which theelectronic device of the second feature is configured so that the secondmetal member is elongated into the housing, and the heat generatingelement is attached to an elongated portion.

According to the third feature, when the elongated portion isarbitrarily elongated, the attaching position of the heat generatingelement can be freely set, so that an electronic component in thehousing can be placed in a very easy manner or the degree of freedom indesign is improved. On the other hand, since the elongated portion iscoupled to the first metal member facing the outside of the housing,heat generated by the heat generating element can be easily radiated tothe outside. Therefore, the electronic device has excellent heatradiating properties.

A fourth feature of the invention is an electronic device in which theelectronic device of any one of the first to third features isconfigured so that a rear portion of the housing is opened, and the rearopening of the housing is covered with the first metal member.

According to the fourth feature, a metal member having a large area canbe used as the first metal member, and hence heat generated by the heatgenerating element can be easily conducted to the outside. Therefore, anelectronic device of further excellent heat radiating properties can beobtained.

A fifth feature is an electronic device in which the electronic deviceof any one of the first to fourth features is configured so that asupport member attaching portion is disposed in a portion of the firstmetal member facing the outside of the housing.

According to the fifth feature, since the support member attachingportion is disposed in a portion of the first metal member facing theoutside of the housing, the device can be used for attaching a supportmember.

A sixth feature is an electronic device in which the electronic deviceof the fifth feature is configured so that the support member attachingportion can be grounded through a support member attached to the supportmember attaching portion.

According to the sixth feature, when the device is attached to thesupport member, the member can perform a shielding function againstelectrical noises generated from an internal electronic component.

A seventh feature is an electronic device having: a housing in which arear portion is opened, and which has a terminal block attaching hole ina front side; and device configuring members which can be incorporatedinto the housing through the housing rear opening, the deviceconfiguring members including at least: a circuit board on which theterminal block is mounted; a heat generating element; and a metalmember, the circuit board being accommodated in the housing so that,under the incorporated state, the terminal block positionallycorresponds to the terminal block attaching hole in the front side ofthe housing, the metal member serving under the incorporated state as acovering member for the housing rear opening, the heat generatingelement being attached to at least a portion of the metal member whichis located in the housing.

According to the seventh feature, in addition to the effect of heatradiating properties due to the metal member, assembling of the deviceis completed only by accommodating the device configuring member throughthe housing rear opening. Therefore, assembling is easy, and also thetime period required for assembling is shortened. Since the metal memberserves as a covering member for the rear opening of the housing,moreover, the device itself can be made compact.

An eighth feature of the invention is an electronic device in which theelectronic device of the seventh feature is configured so that, under anintegrated state in which the circuit board is attached to the metalmember, the device configuring member can be accommodated into thehousing through the housing rear opening.

According to the eighth feature, assembling of the device configuringmembers themselves has been already completed, and hence assembling ofthe device configuring members into the housing is further simplified.

A ninth feature is an electronic device having: a housing in which arear portion is opened, and which has a terminal block attaching hole ina front side; and device configuring members which can be incorporatedinto the housing through the housing rear opening, the deviceconfiguring members including at least: a circuit board on which theterminal block is mounted; a heat generating element; and first andsecond metal members, the circuit board being accommodated in thehousing so that, under the incorporated state, the terminal blockpositionally corresponds to the terminal block attaching hole in thefront side of the housing, the first metal member serving under theincorporated state as a covering member for the housing rear opening,the second metal member being formed integrally with the first metalmember, or coupled to the first metal member directly or via anothermetal member, the heat generating element being attached to the secondmetal member, the second metal member being located in the housing underthe incorporated state.

According to the ninth feature, in addition to the effect of heatradiating properties due to the metal members, assembling of the powersource device is completed only by accommodating the device configuringmembers through the housing rear opening. Therefore, assembling is easy,and also the time period required for assembling is shortened. Since thefirst metal member serves as a covering member for the rear opening ofthe housing, moreover, the device itself can be made compact.

A tenth feature of the invention is an electronic device in which theelectronic device of the ninth feature is configured so that, under anintegrated state in which the circuit board is attached to at least oneof the first or second metal member, the device configuring members canbe accommodated into the housing through the housing rear opening.

According to the tenth feature, assembling of the device configuringmembers themselves has been already completed, and hence assembling ofthe device configuring members into the housing is further simplified.

An eleventh feature is an electronic device in which the electronicdevice of the ninth or tenth feature is configured so that the circuitboard includes first and second circuit boards which are respectivelylocated and accommodated in front and rear sides of the housing so as tobe separated from each other in parallel with or in substantiallyparallel with each other, the terminal block is mounted on the firstcircuit board, an electronic component constituting a noise filtercircuit is mounted on the first circuit board, and an electroniccomponent generating electrical noises is mounted on the second circuitboard.

According to the eleventh feature, the first circuit board and thesecond circuit board are separated by a distance in the housing. Evenwhen noises generated from the electric noise generating electroniccomponent mounted on the second circuit board try to be transmittedthrough the air, therefore, the noises are blocked by the first circuitboard. As a result, the possibility that the noises enter the terminalblock mounted on the first circuit board is lowered. Therefore, theelectronic device has excellent noise resistance.

A twelfth feature is an electronic device which has a heat generatingelement in a housing, and in which a rear portion of the housing issupported by a support rail made of a metal, wherein a heat generatingelement attaching member is placed so as to face a rear opening of thehousing, the heat generating element attaching member or the heatgenerating element is enabled to be directly or indirectly in contactwith the support rail under a state where the support rail is attachedto the opening, and the contact allows heat generated by the heatgenerating element to be radiated to a side of the support rail.

According to the twelfth feature, heat radiation can be performedthrough the support rail. Even when the housing is configured by amaterial such as a resin which is inferior in heat radiating propertythan a metal, therefore, heat generated by the heat generating elementin the housing can be efficiently discharged to the outside of thehousing, and the electronic device has excellent noise resistance.Furthermore, the support rail is sufficiently wide and long, and hassufficient heat radiating properties. Consequently, it is not requiredto dispose a heat radiating plate or the like in the housing, and hencethe device can be further miniaturized.

A thirteenth feature is a panel device in which one or more of theelectronic device of claim 12 is accommodated in a panel under a statewhere the device is supported by a support rail, the support rail has acavity, and a heat discharging gas is enabled to be introduced from anoutside of the panel into the cavity and then discharged to the outsideof the panel.

According to the thirteenth feature, when the support rail is passedthrough the panel, the cavity allows, for example, the outside airserving as the heat discharging gas to be introduced from an inlet onone side of the cavity of the support rail, and the outside air isdischarged from an outlet on another side of the cavity. In thedischarge of the outside air, heat of the heat generating element in theelectronic device is conducted to the air in the cavity of the supportrail, and the cavity air to which the heat is conducted is discharged tothe outside. Therefore, the heat radiation efficiency with respect tothe head generated by the heat generating element is excellent. Since itis not required to form a suction port in the panel, the air itself inthe panel is isolated from the outside. Unlike the conventional art,consequently, air is not sucked together with dust through a suctionport into the panel, and the air in the panel is not contaminated.Moreover, the support rail can be easily cooled, and hence its heatradiation efficiency can be enhanced more easily. Since a suction portis made unnecessary, the panel can be hermetically sealed so as toattain good waterproofness.

A fourteenth feature is a support rail for supporting an electronicdevice which has a heat generating element inside a housing, wherein thesupport rail has a cavity which passes through the support rail from oneend side to another end side, and a structure in which heat conductedfrom the heat generating element is discharged by a gas that flows intofrom the one end side of the cavity and then flows out from the otherend side.

According to the fourteenth feature, a structure is obtained in whichheat conducted from the heat generating element is discharged via thecavity which passes through from one end side to the other end side, bya gas which flows into from the one end side of the cavity and thenflows out from the other end side. Therefore, it is possible to attainthe same effects as the panel device which uses the support rail.

A fifteenth feature is a support rail in which the support rail of thefourteenth feature is configured so that heat radiating fins aredisposed in the cavity.

According to the fifteenth feature, since heat radiating fins aredisposed in the cavity, it is possible to attain the effect that theheat radiation efficiency can be further enhanced.

In the metal members described above, a metal is used as a constitutingmaterial. The metal members are not restricted to those which arethoroughly configured by a metal. Also a member which partly contains amaterial other than a metal, or that which is integrated or connectedwith a material other than a metal is included in the invention.

The attachment of the heat generating element to the second metal memberhas a broad meaning including all cases where a portion of the heatgenerating element other than leads is attached by screws, bonded byusing an adhesive agent, or closely contacted by applying a pressingforce by using a plate spring, and where the heat generating element isattached to the second metal member by other means in a manner that heatradiation is enabled.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an external perspective view of a power source device relatingto an embodiment of the invention.

FIG. 2 is an exploded perspective view of the embodiment shown in FIG.1.

FIG. 3 is an exploded perspective view of the embodiment shown in FIG.1.

FIG. 4 is a transverse section view showing the internal structure ofthe embodiment with omitting a housing.

FIG. 5 is a block circuit diagram showing the circuit configuration.

FIG. 6 is a section view of main portions of a power source devicerelating to another embodiment of the invention.

FIG. 7 is a perspective view of main portions of a power source devicerelating to a further embodiment of the invention.

FIG. 8 is an external perspective view of a power source device relatingto a still further embodiment of the invention.

FIG. 9 is an exploded perspective view of a power source device relatingto a still further embodiment of the invention.

FIG. 10 is an external perspective view of a housing in a power sourcedevice relating to a still further embodiment of the invention.

FIG. 11 is an external perspective view showing a state where a supportrail is attached to the housing of FIG. 10.

FIG. 12 is a section view of FIG. 11.

FIG. 13 is a partial cutaway view of a control panel showing a statewhere the power source device of FIG. 10 into the panel via a supportrail.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings.

Cases where the electronic device of the invention is applied to a powersource device, particularly to a switching power source device will bedescribed. However, the invention is not restricted to such cases, andmay be of course applied to other power source devices, and also tousual electronic devices which comprises a heat generating element in ahousing.

An embodiment of the invention will be described in detail withreference to FIGS. 1 to 5. FIG. 1 is an external perspective view asseeing a switching power source device (hereinafter, referred to merelyas “power source device”) relating to the embodiment from an obliquelyrear side, FIGS. 2 and 3 are exploded perspective views of the device,FIG. 4 is a transverse section view showing the internal structure withomitting a housing, and FIG. 5 is a circuit diagram of the power sourcedevice.

In the figures, the power source device of the embodiment comprises ahousing 1, two or first and second circuit boards 2 and 3, and a metalmember 4.

The housing 1 includes a material which is inferior in heat radiatingproperty than a metal, such as a resin or a resin and another material.In at least a side portion of the housing 1, particularly, a resin isused as a material, or a resin is used as a main material. The housing 1has a rectangular cylindrical shape which is configured by a frontportion 5 and four side portions 6 to 9 so as to have an opening 10 in arear side. In the housing 1, four edges where the side portions 6 to 9are adjacent to each other are formed as recesses 11 which elongate fromthe front side to the rear side. Each of the recesses 11 has a screwhole 12 in a rear portion (FIG. 2). The housing 1 has a recess 13 in afront portion, and plural insulation flanges 14 are integrally formed inthe recess 13 at regular intervals. Terminal block attaching holes(which are not shown in the drawings) are formed in a bottom portion inthe recess between the insulation flanges 14. In the side portions 6 to9 of the housing 1, a large number of heat radiating slit holes 15 arejuxtaposed in a grid-like manner. A cutaway 16 for passing a DIN rail(in a broad sense, the type of the rail is not restricted to a DIN railand may be a support rail) which is used as a support member that willbe described later is formed in each of the rear ends of the pair ofopposed side portions 6 and 8 of the housing 1.

The first circuit board 2 is accommodated on the front side in thehousing 1, and the second circuit board 3 is accommodated on the rearside in the housing 1. As shown in FIG. 4, plural terminal blocks 17 aremounted on the surface (this surface is a face opposed to the inner faceof the front side of the housing 1) of the first circuit board 2, so asto correspond to the formation intervals of the terminal block attachingholes. A terminal clamp 18 and a terminal 19 are attached to each of theterminal blocks 17. The lower ends of the terminal blocks 17 are passedthrough the first circuit board 2 and then fixed to the rear face of theboard by soldering. Electronic components mounted on the circuit boards2 and 3 have the circuit configuration shown in FIG. 5. The circuitconfiguration will be briefly described.

The circuit has a pair of input terminals 20 and a pair of outputterminals 21. Between the pair of input terminals 20 and the pair ofoutput terminals 21, the circuit has a noise filter circuit 22, an inputrectifying and smoothing circuit 23, a converter transformer 24, and anoutput rectifying and smoothing circuit 25. The circuit further has aswitching transistor 26, a driving circuit 27 for the switchingtransistor 26, and a switch circuit 28. An AC voltage through the pairof input terminals 20 is passed through the noise filter circuit 22, andthen converted into a DC voltage by the input rectifying and smoothingcircuit 23, and the DC voltage is input into the primary winding of theconverter transformer 24. On the other hand, the switching transistor 26is turned on and off via the driving circuit 27 by a signal from theswitch circuit 28, and a voltage which is induced in the secondarywinding of the converter transformer 24 is again converted into a DCvoltage by the output rectifying and smoothing circuit 25 to be outputto the pair of output terminals 21.

As electronic components constituting such a circuit, the pair of inputterminals 20 and the pair of output terminals 21 which are to beconnected to ones of the terminal block 17 are on the first circuitboard 2. Furthermore, electronic components 29 constituting the noisefilter circuit 22, such a coil and a capacitor, and electroniccomponents 30 constituting the input rectifying and smoothing circuit23, such as a capacitor and a diode are mounted on the first circuitboard 2. By contrast, the converter transformer 24, electroniccomponents 30 constituting the output rectifying and smoothing circuit25, such as a diode 31 and a capacitor, the switching transistor 26, andelectronic components such as a switch circuit are mounted on the secondcircuit board 3. However, illustration of the electronic components areoften omitted.

A heating element in the power source device is configured by, forexample, the switching transistor 26, and the rectifying diode 31 in theoutput rectifying and smoothing circuit 25. Lead wires 26 a and 31 a ofthe switching transistor 26 and the rectifying diode 31 are fixed to thesecond circuit board 3 by soldering. Electrical connections between thecircuit boards 2 and 3 are realized by plural lead wires 32 and 33.

As shown in FIG. 2, the metal member 4 is integrally configured by afirst plate member portion (corresponding to the first metal member) 35,and second plate member portions 36 (corresponding to the second metalmember). The first plate member portion 35 has a rectangular shape in aplan view, and a structure for attaching a DIN rail 34. By contrast, thesecond plate member portions 36 are formed by bending the sides of thefirst plate member portion 35 so as to be raised forward andperpendicularly form the sides, thereby configuring a pair of right andleft portions.

A screw attaching hole 37 is disposed in each of four corners of thefirst plate member portion 35. The screw attaching holes 37 correspondto the screw holes 12 disposed in a rear portion of the recesses 11which are located in the four corners of the housing 1, respectively. ADIN rail attaching groove 38 which has a width enabling a DIN rail to bepassed in a DIN rail attaching direction is disposed in the back face ofthe first plate member portion 35. A DIN rail engaging member 40 made ofa resin is disposed in a groove 39 which is perpendicular to the centerof the attaching groove 38 and communicates therewith. The resin-madeDIN rail engaging member 40 elastically protrudes toward the attachinggroove 38 so as to be engageable with a DIN rail.

Each of the second plate member portions 36 has recesses 41 which areengageable with the first circuit board 2, and steps 42 which areengageable with the second circuit board 3. On the other hand, the heatgenerating elements or the switching transistor 26 and the rectifyingdiode 31 are soldered onto the second circuit board 3 as describedabove. The heat generating elements are placed on the second circuitboard 3 so as to be in close contact with the surfaces of the platemember portions 36, respectively.

In assembling of the configuring members of the power source device ofthe embodiment into the housing 1, the recesses 41 and the steps 42disposed in the second plate member portions 36 of the metal member 4are engaged with the circuit boards 2 and 3 on which predeterminedelectronic components are mounted, respectively. Next, the switchingtransistor 26 and the rectifying diode 31 are attached to the secondplate member portions 36 by screws which are not shown, respectively.The first plate member portion 35 is assembled so as to cover theopening 10 in the rear portion of the housing 1 to configure the rearportion of the housing 1, thereby completing assembling of the powersource device.

The thus assembled power source device of the embodiment is attached tothe DIN rail 34. In this case, when the DIN rail 34 is grounded, themember 4 is grounded through the DIN rail 34 because the first platemember portion 35 is in direct contact with the DIN rail 34. Even whenelectrical noises are generated from components in the power sourcedevice, such as the converter transformer 24 or the switching transistor26, therefore, the components are shielded, and hence it is possible tosuppress the noises from adversely affecting the surroundings.

In the embodiment, the first plate member portion 35 is grounded.Alternatively, the second plate member portions 36 may be deformed so asto be electrically connected to the DIN rail 34 to be grounded. Thefirst plate member portion 35 or the second plate member portions 36 maybe electrically connected via a lead wire to the DIN rail 34 to begrounded. When such a connection is performed, the grounding effect isfurther enhanced.

When the DIN rail 34 is not grounded, the first plate member portion 35is not grounded trough the DIN rail 34. Alternatively, for example, aground line may be placed along the DIN rail 34, and the first platemember portion 35 may be made in contact with the line to be grounded.

The size of the second plate member portions 36 may be made larger thanthat in the embodiment, so that the internal electronic components arecovered by the plate member portions 35 and 36, thereby enhancing theshielding effect.

In the power source device of the embodiment, at least the side portionof the housing 1 is made of a resin. Unlike the conventional art examplein which the whole of the housing is made of a metal, therefore, it isnot required to ensure an insulation distance from the internalelectronic components. Consequently, the housing can be miniaturized andlightened, so that the power source device can be miniaturized andlightened.

In the power source device of the embodiment, although the housing 1 isconfigured by a resin which is inferior in heat radiating property, thesecond plate member portion 35 faces in a large area to the outside soas to configure the rear portion of the housing 1. Furthermore, thefirst plate member portion 35 and the second plate member portions 36are formed by a single member. Therefore, heat generated by heatgenerating elements attached to the second plate member portions 36 iseasily conducted from the second plate member portions 36 to the firstplate member portion 35, with the result that it is possible to obtain apower source device which is very excellent in heat radiating property.

The second plate member portions 36 may be called a heat radiatingmember, and the first plate member portion 35 may be called a DIN railattaching portion or a shielding portion. Alternatively, the whole ofthe plate member portions 35 and 36 may be called a heat radiatingmember. In the case where the whole of the plate member portions 35 and36 is called a heat radiating member, the member 4 may be partlyelongated into the housing 1, an elongated portion may be formed as thesecond plate member portions 36 to serve as a heat radiating member, andthe remaining portion may be formed as the first plate member portion 35and called a DIN rail attaching portion, a shielding portion, or a heatradiating member.

The groove 38 for attachment to a DIN rail is formed in the back face ofthe first plate member portion 35. However, the shape of the groove 38is an example. The back face may be formed as a ridge, and a supportrail having a U-like section shape, or a support rail having a T-likesection shape such as a DIN rail may be attached to the ridge.

The second plate member portions 36 have a flat face. Alternatively, theportions may be formed into a fin-like shape so as to further enhancethe heat radiating effect.

The number of the internal circuit boards 2 and 3 is two. The number isnot restricted to the value, and any number of circuit boards may beused.

The embodiment is configured so that heat generating elements areattached to the second plate member portions 36. Alternatively, aconfiguration may be employed in which, while the second plate memberportions 36 remain as they are or are omitted, a heat generating elementis attached to a place of the first plate member portion 35 and facingthe inside of the housing 1.

The metal member 4 is not restricted to a member the whole of which isconfigured by a metal, and may be a member which is partly configured bya metal. For example, a portion to which a heat generating element isattached is made of a metal, a portion to which a DIN rail is to beattached is made of a metal, the places are connected to each other bymeans of a metal, and the other portion is configured by a materialother than a metal. In the invention, the metal member is not requiredto be thoroughly configured by a metal, as far as the whole or a part ofthe effects of the invention can be attained. Also a member whichcontains in part a material other than a metal is interpreted as themetal member.

The metal member 4 is not restricted to a member the whole of which isconfigured by a metal, and which covers the rear opening of the housing1. As the metal member 4, a member in which a metal plate and a resinplate are integrated or coupled with each other may be used. The membermay cover the rear opening of the housing 1.

The power source device of the embodiment is of the type in which thedevice is to be attached to a DIN rail serving as a supporting member.The embodiment may be applied also to a type in which a floor or a workbench is used as a supporting member and the device is placed on themember. Furthermore, the embodiment may be applied also to a type inwhich the device is attached by screws to an appropriate panel faceserving as a supporting member. In such cases, the first plate memberportion 35 may be grounded by adequately making in contact or connectingwith an appropriate grounding member, an apparatus, or a lead.

In the embodiment described above, the first plate member portion 35 andthe second plate member portions 36 are formed as an integratedstructure by the single member 4. Alternatively, both the plate memberportions 35 and 36 may be separately configured as shown in FIG. 6, andfixedly connected to each other by other connecting means such as ascrew 41. In this case, the first plate member portion 35 and the secondplate member portions 36 are directly coupled to each other. The platemember portions 35 and 36 may be indirectly coupled via another platemember portion (member) between the plate member portions 35 and 36. Itis not necessary to restrict the number of coupled plate memberportions.

In the embodiment described above, each of the second plate memberportions 36 is disposed on one of both sides of the first plate memberportion 35. Alternatively, plural second plate member portions 36 may bedisposed on each of the sides, or, as shown in FIG. 7, plural secondplate member portions 36 may be disposed on one side portion of thefirst plate member portion 35, and heat generating elements may beattached to the second plate member portions 36, respectively.

The embodiment described above has a structure which has no cover. Asshown in FIG. 8, the housing 1 may be configured so as to be split intoa housing body portion 42 and a cover 43.

In the embodiment described above, the rear portion of the housing 1 isopened. Alternatively, as shown in FIG. 9, the front portion of thehousing is opened, a structure may be employed in which the cover 43 isattached as described above, and the rear portion of the housing 1 isclosed. The first plate member portion 35 and the second plate memberportions 36 may be split so as to be formed as separate members. In thiscase, the circuit boards 2 and 3 are engaged with the second platemember portions 36, and these members are inserted from the frontportion of the housing body portion 42. Thereafter, projections 45 whichare located on both sides of the first plate member portion 35 arepassed through slits 44 formed in the rear portion of the housing bodyportion 42, respectively. After the plate member portions 35 and 36 arepositioned, screws (not shown) which have been passed through screwholes 46 of side portions of the housing body portion 42 are passedthrough screw holes 47 and 48 of the plate member portions 35 and 36,respectively, whereby the plate member portions 35 and 36 are coupled toeach other in the housing 42.

In FIG. 9, the rear groove 39 of the housing 1 for attachment to a DINrail is omitted. It is a matter of course that such a groove may beformed so as to be attachable to a DIN rail.

In the embodiment described above, when device configuring members areconfigured by: the first circuit board 2 on which the terminal blocks 17and the electronic components 29 for the noise filter circuit aremounted; the second circuit board 3 on which the electronic componentsthat easily generate electric noises, such as the converter transformer24 are mounted; the heat generating elements 26 and 31 such as theswitching transistor and the rectifying diode; and the metal member 4consisting of the first and second plate member portions 35 and 36, theabove-mentioned effects are attained on heat radiating properties due tothe plate member portions 35 and 36. Furthermore, assembling of thepower source device is completed only by accommodating the deviceconfiguring members through the rear opening 10 of the housing 1.Therefore, assembling is easy, and also the time period required forassembling is shortened. Since the first plate member portion 35 servesas a covering member for the rear opening 10 of the housing 1, moreover,the power source device itself can be miniaturized.

In this case, the circuit boards 2 and 3 are respectively located andaccommodated in front and rear sides of the housing 1 so as to beseparated from each other in parallel with or in substantially parallelwith each other, and hence the power source device can be thinned. Thefirst circuit board 2 and the second circuit board 3 are separated fromeach other by a predetermined distance in the housing 1. The firstcircuit board 2 is located between the terminal block 17 and the secondfirst circuit board 3. According to this structure, even when noisesgenerated from the electric noise generating electronic componentsmounted on the second circuit board 3 try to be transmitted through theair, the noises are blocked by the first circuit board 2. As a result,the possibility that the noises enter the terminal block 17 mounted onthe first circuit board 2 is lowered, and the noises are prevented fromleaking from the terminal block 17 to the outside. Therefore, a powersource device which is excellent in noise processing is obtained. Thedevice configuring members are integrated by attaching the circuitboards 2 and 3 to at least one of the first or second plate memberportion 35 or 36, particularly, in the embodiment, the second platemember portions 36. When accommodation into the housing 1 is to beperformed through the front opening of the housing 1, therefore,assembling of the device configuring members themselves has been alreadycompleted. As a result, the work of accommodating the device configuringmembers into the housing 1 is completed by one-touch operation, so thatthe easiness of the assembling is remarkably improved.

A switching power source which is an example of a power source devicerelating to another embodiment of the invention will be described withreference to FIGS. 10 to 12.

FIG. 10 shows the external configuration of the housing 1 of theswitching power source. Portions corresponding to those of FIG. 1 aredenoted by the same reference numerals. In the embodiment, necessity ofdisposing a heat radiating plate or the like in the housing iseliminated, whereby the power source device can be further miniaturized.

As shown in FIGS. 10 and 11, a cutaway 50 for supporting and passing asupport rail 34 such as a DIN rail is formed in a rear end face of eachof the side portions 6 and 8 of the housing 1. Each of the cutaways 50has a front engaging face 51 which is to be engaged with a front faceportion 34 a of the support rail 34, and rear engaging faces 52 whichare to be engaged with a rear face portion 34 b. The rear engaging faces52 cooperate with the front engaging face 51 to constitute gaps 53 whichare to be engaged with elongated portions 34 b on both the sides of thesupport rail 34, respectively. Therefore, the elongated portions 34 b ofthe support rail 34 can be passed through the gaps 53 between theengaging faces 51 and 52.

As shown in FIG. 11, the support rail 34 comprises a body portion 34 c,and the elongated portions 34 b which vertically elongate from the upperand lower sides of the body portion 34 c, respectively. The innerportion of the body portion 34 c is formed as a cavity 34 d which ispassed from one end side to the other end side. Plural heat radiatingfins 34 e for further enhancing the heat radiation efficiency aredisposed in the cavity 34 d.

The support rail 34 is inserted into the cutaways 50 so as to cover therear opening 10 of the housing 1, to be attached thereto, as shown inFIG. 11. The attached state will be described with reference to FIG. 12.In the housing 1, a substrate 53 for attaching the switching transistor26 and the diode 31 (hereinafter, referred to as the heat generatingelements 26 and 31) is equipped. Lead wires 26 a and 31 a of the heatgenerating elements 26 and 31 are soldered to the attachment substrate53 in a state where the lead wires are bent, and the heat generatingfaces of the heat generating elements 26 and 31 are placed so as to bein contact with the attachment substrate 53. The attachment substrate 53is fixed in the housing 1 so as to be in contact with the front faceportion 34 a of the support rail 34 via an electrical insulating member54 which is superior in heat radiating property, such as heat conductiverubber or the like. Therefore, the electrical insulating member may becalled a heat conductive member.

Therefore, heat generated by the heat generating elements 26 and 31 isconducted from the electrical insulating member 54 to the support rail34, to be radiated from the support rail 34. Even when the housing 1 isconfigured by a material such as a resin which is inferior in heatradiating property than a metal, heat generated by the heat generatingelements 26 and 31 in the housing 1 can be efficiently discharged fromthe support rail 34 to the outside of the housing 1. Therefore, a powersource device such as a switching power source which is excellent inheat radiating property can be obtained. As a result, it is not requiredto dispose a heat radiating plate or the like for radiating heatgenerated by the heat generating elements 26 and 31, in the housing 1,whereby the power source device can be further miniaturized.

As shown in FIGS. 11 and 12, each of the heat generating elements 26 and31 is in contact with the front face portion 34 a of the support rail 34via the attachment substrate 53. Alternatively, the direction of theattachment substrate 53 may be reversed so as to form a configuration inwhich the heat generating elements 26 and 31 are directly in contactwith the electrical insulating member 54.

Furthermore, the member 54 is not always necessary and may be omitted asfar as insulation between the elements is ensured. On the other hand,the attachment substrate 53 or the heat generating elements 26 and 31may be directly in contact with the lower face portion 34 a of thesupport rail 34.

Moreover, the attachment substrate 53 may be formed as a heat generatingelement attaching member, or the attachment substrate 53 and the member54 may be combined to be formed as a heat generating element attachingmember.

According to the embodiment of FIGS. 10 to 12, it is not necessary toincorporate a heat radiating plate in the housing 1, and hence the powersource device can be miniaturized. Heat radiation can be performedthrough the support rail 34, and the heat radiating capacity can besufficiently obtained. Therefore, it is possible to incorporate a heatgenerating element of a large capacity.

A case where a plurality of such power source devices are accommodatedand used in a control panel (table) under a state the devices aresupported by the support rail 34 will be described.

In a power source device of a structure of the conventional art, heatgenerated by the device easily stagnates in the control panel.Therefore, a suction port is disposed on one side of the control panel,and air is discharged from the other side by an exhaust fan so that theheat in the control panel is discharged together with the dischargedair. As a result, the conventional structure has a defect that air issucked together with dust through the suction port into the controlpanel, and the air in the panel is contaminated. When air discharge isto be sufficiently performed only by an exhaust fan, it is necessary todischarge air by a large exhaust fan. Since the suction port is formedin the control panel, there is a great disadvantage that, when the panelis disposed in a place which is exposed to the weather or is moist, awaterproofing countermeasure which is high in cost is required.

The support rail 34 for supporting a power source device 55 of theembodiment has the cavity 34 d which is passed from one end side to theother end side in the body portion 34 c. As shown in FIG. 13, thesupport rail 34 is passed through a control panel 56. Therefore, thespace in the control panel is separated from the cavity 34 d in thesupport rail. For example, the outside air is taken in as a heatdischarging gas from the inlet on one side of the cavity 34 d disposedin the support rail 34, and the outside air is discharged from theinside of the cavity 34 d to the other end outlet. In the discharge ofthe outside air, therefore, heat generated by heat generating elementsincorporated in the power source device 55 in the control panel 56 istransmitted to the air in the cavity 34 d of the support rail 34, andthen discharged to the outside, resulting in a high heat radiationefficiency.

Furthermore, since it is not required to form another suction port inthe control panel 56, the air itself in the control panel 56 is isolatedfrom the outside. Unlike the conventional art, consequently, air is notsucked together with dust through a suction port into the control panel56, and the air in the control panel 56 is not contaminated.

Moreover, the support rail 34 can be easily cooled, and hence its heatradiation efficiency can be enhanced more easily.

Since the control panel 56 can be hermetically sealed, the panel may beconfigured so as to have good waterproofness.

The support rail 34 may be fixed to the control panel 56 by screws. Theflowing direction of air in the cavity 34 d of the support rail 34 maybe controlled by a fan 57. However, this is not essential. Detailedillustration of the sate of attaching the fan 57 to the support rail 34is omitted.

INDUSTRIAL APPLICABILITY

The invention is not restricted to an electronic device such as a powersource device, and may be applied to another electronic device whichcomprises a heat generating element inside a housing.

What is claimed is:
 1. An electronic device comprising: a housing inwhich a rear portion is opened; a first metal member facing an insideand an outside of said housing and covering the rear opening of saidhousing; a second metal member provided for said first metal member andpositioned within said housing; and a heat generating element arrangedin a manner so as to be attached to said second metal member in saidhousing, wherein a support member attaching portion for attaching saidhousing to a support member detachably is provided for a portion of saidfirst member facing the outside of said housing.
 2. An electronic deviceaccording to claim 1, wherein said support member attaching portion canbe grounded through a support member attached to said support memberattaching portion.
 3. An electronic device having: a housing in which arear portion is opened, and which has an attaching hole for attaching aterminal block in a front side; and a device configuring member whichcan be incorporated into said housing through the housing rear opening,said device configuring member including at least: a circuit board onwhich said terminal block is mounted; a heat generating element; and ametal member, said circuit board being accommodated in said housing sothat said mounted terminal block positionally corresponds to saidattaching hole of said housing, said metal member serving as a coveringmember for said housing rear opening, said heat generating element beingattached to at least a portion of said metal member which is located insaid housing.
 4. An electronic device according to claim 3, wherein,under an integrated state in which said circuit board is attached tosaid metal member, said device configuring member can be accommodatedinto said housing through said housing rear opening.
 5. An electronicdevice having: a housing in which a rear portion is opened, and whichhas an attaching hole for attaching a terminal block in a front side;and a device configuring member which can be incorporated into saidhousing through said housing rear opening, said device configuringmember including at least: a circuit board on which said terminal blockis mounted; a heat generating element; and first and second metalmembers, said circuit board being accommodated in said housing so thatsaid mounted terminal block positionally corresponds to said attachinghole of said housing, said first metal member serving as a coveringmember for said rear opening of said housing in a state in which saidfirst metal member is incorporated into said housing, and said secondmetal member being provided for said first metal member and accommodatedin said housing, said heat generating element being attached to saidsecond metal member.
 6. An electronic device according to claim 5,wherein said device configuring member is an integrated material inwhich said circuit board is attached to at least one of said first orsecond metal member, said device configuring member can be accommodatedinto said housing through said housing rear opening.
 7. An electronicdevice according to claim 5, wherein said circuit board includes firstand second circuit boards which are respectively located andaccommodated in front and rear sides of said housing so as to beseparated from each other in parallel with or in substantially parallelwith each other, said terminal block is mounted on said first circuitboard, an electronic component constituting a noise filter circuit ismounted on said first circuit board, and an electronic componentgenerating electrical noises is mounted on said second circuit board. 8.An electronic device according to claim 3 or 5, wherein a rear portionof a housing is supported by a support rail made of a metal, said heatgenerating element attaching member is placed so as to face a rearopening of said housing, said heat generating element attaching memberor said heat generating element is enabled to be directly or indirectlyin contact with said support rail under a state where said support railis attached to said opening, and the contact allows heat generated bysaid heat generating element to be radiated to a side of said supportrail.